APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

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APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by APOD Robot » Tue Mar 19, 2019 4:06 am

Image Abell 370: Galaxy Cluster Gravitational Lens

Explanation: What are those strange arcs? While imaging the cluster of galaxies Abell 370, astronomers noticed an unusual arc. The arc wasn't understood right away -- not until better images showed that the arc was a previously unseen type of astrophysical artifact of a gravitational lens, where the lens was the center of an entire cluster of galaxies. Today, we know that this arc, the brightest arc in the cluster, actually consists of two distorted images of a fairly normal galaxy that happens to lie far in the distance. Abell 370's gravity caused the background galaxies' light -- and others -- to spread out and come to the observer along multiple paths, not unlike a distant light appears through the stem of a wine glass. Almost all of the yellow images featured here are galaxies in the Abell 370 cluster. An astute eye can pick up many strange arcs and distorted arclets, however, that are actually gravitationally lensed images of distant normal galaxies. Studying Abell 370 and its images gives astronomers a unique window into the distribution of normal and dark matter in galaxy clusters and the universe.

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by Ann » Tue Mar 19, 2019 6:06 am

Don't have time to write much, but this is a splendid and fantastic picture. Thank you, NASA, ESA and Hubble! Thank you, Rogelio Bernal Andreo! :D :yes: :clap:

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by De58te » Tue Mar 19, 2019 9:37 am

Nice picture. The first question that pops into my mind is Abell 370 so named because there are 370 individual galaxies in it? Doing a google search I find there is also an Abell 2218 galaxy cluster. Presumably there are 2,218 galaxies in it?

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by BDanielMayfield » Tue Mar 19, 2019 12:46 pm

De58te wrote:
Tue Mar 19, 2019 9:37 am
Nice picture. The first question that pops into my mind is Abell 370 so named because there are 370 individual galaxies in it? Doing a google search I find there is also an Abell 2218 galaxy cluster. Presumably there are 2,218 galaxies in it?
No. Looking up Abell catalog shows that location on the sky dictiated his numbering scheme.
In the catalog as originally published the clusters were listed in increasing order of right ascension. Equatorial coordinates (right ascension and declination) were given for the equinox of 1855 (the epoch of the Bonner Durchmusterung) and galactic coordinates for 1900.
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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by orin stepanek » Tue Mar 19, 2019 12:54 pm

Wow: galaxies all over the place! I'd be hard pressed to tell some of the lensed ones, except for the stretched out ones! Either way; I couldn't began to count them all! Great APOD! 8-) :D
Orin

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by sillyworm 2 » Tue Mar 19, 2019 1:18 pm

What an astounding and probably the finest example of lensing I have seen.The clarity of those distant galaxies!!! Anyone have an idea as to why we cannot post to the apods at times? 2 days ago I could not post...not the first time this has happened.My question was about the twin jets emenating from the core of the mentioned galaxy(2 apods ago).It was mentioned that the jets run the "length" of the galaxy.I was wondering if the jets passed through the arms would the jets negate any chance of life on any planets in it's path?

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by starsurfer » Tue Mar 19, 2019 1:54 pm

De58te wrote:
Tue Mar 19, 2019 9:37 am
Nice picture. The first question that pops into my mind is Abell 370 so named because there are 370 individual galaxies in it? Doing a google search I find there is also an Abell 2218 galaxy cluster. Presumably there are 2,218 galaxies in it?
The name comes from the fact that it is the 370th galaxy cluster to be catalogued by George Abell in his catalogue of galaxy clusters.

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by starsurfer » Tue Mar 19, 2019 1:55 pm

To me this image is like the galaxy equivalent of a star trail photo.

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by BDanielMayfield » Tue Mar 19, 2019 2:08 pm

De58te wrote:
Tue Mar 19, 2019 9:37 am
Nice picture. The first question that pops into my mind is Abell 370 so named because there are 370 individual galaxies in it? Doing a google search I find there is also an Abell 2218 galaxy cluster. Presumably there are 2,218 galaxies in it?
And as to the total number of clusters in Abell's cluster catalog there is this:
The Abell catalog of rich clusters of galaxies is an all-sky catalog of 4,073 rich galaxy clusters of nominal redshift z ≤ 0.2. This catalog supplements a revision of George O. Abell's original "Northern Survey" of 1958, which had only 2,712 clusters, with a further 1,361 clusters – the "Southern Survey" of 1989, published after Abell's death by co-authors Harold G. Corwin and Ronald P. Olowin from those parts of the south celestial hemisphere that had been omitted from the earlier survey.
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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by b92541 » Tue Mar 19, 2019 3:00 pm

great photo.
Does anyone know of an on-line article that expains how they manipulate the arcs so they can tell what they are?
Thanks,
Jim...

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by neufer » Tue Mar 19, 2019 4:13 pm

https://en.wikipedia.org/wiki/Arnolfini_Portrait wrote: <<The Arnolfini Portrait (or The Arnolfini Wedding, The Arnolfini Marriage, the Portrait of Giovanni Arnolfini and his Wife, or other titles) is a 1434 oil painting on oak panel by the Early Netherlandish painter Jan van Eyck. It forms a full-length double portrait, believed to depict the Italian merchant Giovanni di Nicolao Arnolfini and his wife, presumably in their home in the Flemish city of Bruges.

It is considered one of the most original and complex paintings in Western art, because of its beauty, complex iconography, geometric orthogonal perspective, and expansion of the picture space with the use of a mirror. The portrait has been considered by Erwin Panofsky and some other art historians as a unique form of marriage contract, recorded as a painting. Signed and dated by van Eyck in 1434, it is, with the Ghent Altarpiece by the same artist and his brother Hubert, the oldest very famous panel painting to have been executed in oils rather than in tempera.

Van Eyck used the technique of applying layer after layer of thin translucent glazes to create a painting with an intensity of both tone and colour. The glowing colours also help to highlight the realism, and to show the material wealth and opulence of Arnolfini's world. Van Eyck took advantage of the longer drying time of oil paint, compared to tempera, to blend colours by painting wet-in-wet to achieve subtle variations in light and shade to heighten the illusion of three-dimensional forms. The medium of oil paint also permitted van Eyck to capture surface appearance and distinguish textures precisely. He also rendered the effects of both direct and diffuse light by showing the light from the window on the left reflected by various surfaces. It has been suggested that he used a magnifying glass in order to paint the minute details such as the individual highlights on each of the amber beads hanging beside the mirror.

The small medallions set into the frame of the convex mirror at the back of the room show tiny scenes from the Passion of Christ and may represent God's promise of salvation for the figures reflected on the mirror's convex surface. The mirror itself may represent the eye of God observing the vows of the wedding. The mirror reflects two figures in the doorway, one of whom may be the painter himself.

According to one author "The painting is often referenced for its immaculate depiction of non-Euclidean geometry", referring to the image on the convex mirror. Assuming a spherical mirror, the distortion has been correctly portrayed, except for the leftmost part of the window frame, the near edge of the table and the hem of the dress.

The little dog symbolizes fidelity (fido), loyalty, or can be seen as an emblem of lust, signifying the couple's desire to have a child. Unlike the couple, he looks out to meet the gaze of the viewer.

The green of the woman's dress symbolizes hope, possibly the hope of becoming a mother. Her white cap could signify purity, but probably signifies her being married. Behind the pair, the curtains of the marriage bed have been opened; the red curtains might allude to the physical act of love between the married couple.

The single candle in the left-front holder of the ornate six-branched chandelier is possibly the candle used in traditional Flemish marriage customs. Lit in full daylight, like the sanctuary lamp in a church, the candle may allude to the presence of the Holy Ghost or the ever-present eye of God. Alternatively, Margaret Koster posits that the painting is a memorial portrait, as the single lit candle on Giovanni's side contrasts with the burnt-out candle whose wax stub can just be seen on his wife's side, evoking a common literary metaphor: he lives on, she is dead.

The cherries present on the tree outside the window may symbolize love. The oranges which lie on the window sill and chest may symbolize the purity and innocence that reigned in the Garden of Eden before the Fall of Man. They were uncommon and a sign of wealth in the Netherlands, but in Italy were a symbol of fecundity in marriage. The fruit could more simply be a sign of the couple's wealth since oranges were very expensive imports.>>
Art Neuendorffer

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by zendae1 » Tue Mar 19, 2019 5:15 pm

Well, that painting is as amazing as the APOD.
How are there no brush strokes at all? Did he use egg to vanquish them? How long did it take him to paint this? How big is the painting?

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by neufer » Tue Mar 19, 2019 6:29 pm

zendae1 wrote:
Tue Mar 19, 2019 5:15 pm

How big is the painting?
Dimensions: 82.2 cm × 60 cm; oak panel 84.5 cm × 62.5 cm
Art Neuendorffer

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by Avalon » Tue Mar 19, 2019 9:35 pm

There is a galaxy not far from the center of the image at 1 o'clock that resembles a ring galaxy only it has a bright center and appears to be barred. However, the arms seem to make a ring instead of spiral arms. I find its appearance unique. Does it fit into any certain classification of galaxy?

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by neufer » Tue Mar 19, 2019 10:50 pm

b92541 wrote:
Tue Mar 19, 2019 3:00 pm

Does anyone know of an on-line article that expains how they manipulate the arcs so they can tell what they are?
Each individual galaxy should have its own unique identifying spectra/red shift.

If 2 to 4 distorted galactic images have the same spectra/red shift then they represent a single lens distorted galaxy.
Art Neuendorffer

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by neufer » Wed Mar 20, 2019 12:21 am

Avalon wrote:
Tue Mar 19, 2019 9:35 pm

There is a galaxy not far from the center of the image at 1 o'clock that resembles a ring galaxy only it has a bright center and appears to be barred. However, the arms seem to make a ring instead of spiral arms. I find its appearance unique. Does it fit into any certain classification of galaxy?
  • A barring galaxy :?:
https://en.wikipedia.org/wiki/Arp_147
https://en.wikipedia.org/wiki/NGC_1300
Art Neuendorffer

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by sillyworm 2 » Wed Mar 20, 2019 12:50 am

No ideas for my above question? Sorry I did not post on the apod of 2 days ago. I did try.Not sure why my posts don't finish loading.It is a very interesting question! Isn't that what science is all about?

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by neufer » Wed Mar 20, 2019 2:34 am

sillyworm 2 wrote:
Wed Mar 20, 2019 12:50 am

No ideas for my above question? Sorry I did not post on the apod of 2 days ago. I did try.Not sure why my posts don't finish loading.It is a very interesting question! Isn't that what science is all about?
It might have helped if you had posted your question in the relevant thread:

http://asterisk.apod.com/viewtopic.php?f=9&t=39271 ...which you can do at anytime.

(I, personally, bookmark active topics : http://asterisk.apod.com/search.php?sea ... ive_topics
to check out the latest posts even if they are in very old threads.)
----------------------------------------------------------------------------------------------
You wish to know if the M106 jets are life threatening to solar systems tens of light years distant in its path.
http://adsabs.harvard.edu/abs/1995ApJ...440..181C wrote:
<<The ROSAT High Resolution Interferometer (HRI) and Position Sensitive Proportional Counter (PSPC) detectors have been used to study the soft X-ray emission of the nearby SABbc galaxy NGC 4258 (M106). The helically twisted, nuclear jets, previously detected in radio continuum and visual emission-line studies, are found to dominate the X-ray images. After correcting pointing errors of up to +/- 7 sec in our HRI observation, we find that the southeast jet is spatially unresolved transversely along much of its 5 kpc length. The northwest jet is more diffuse, and the extensive radio 'plateaus' also emit X-rays. The energy spectrum of the jets from the PSPC exposure is noisy but is best fitted as a Raymond-Smith plasma with kT = 0.3 keV, log NH approximately = 20.0/sq cm, and luminosity 1.6 x 1040 ergs/s between 0.1 and 2.4 keV. Gas at this temperature can arise from planar shocks of 500 km/s and may have been entrained as the jets scrape along the molecular clous [sic] that are known to be adjacent to the jets. The range of radial velocities from our published visual emission-line spectra of the jet are consistent with such a shock speed. We estimate that the mass of hot gas in the jets is 6 x 104 (1/cc/ne) solar mass, with ne the average electron density. The inferred pressure of hot gas in the southeast jet may be similar to the radio equipartition pressure and to the ambient pressure of the interstellar medium (ISM). The X-ray spectral fit is poor above 0.7 keV and requires an additional hard component that peaks near the nucleus.>>
While not being an expert on "molecular clous" my guess is that such a distant (Earth is 8.0 kpc from galactic center) jet would not pose any additional threat to life.
  • The Earth is, itself, bombarded both by high energy cosmic rays & by flares from a very near star and life persists.

    Soft X-rays are easily absorbed in air; the attenuation length of 600 eV X-rays in water is less than 1 micrometer.
Art Neuendorffer

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by sillyworm 2 » Wed Mar 20, 2019 4:25 pm

Thanks Art....as to posting it in the pertinent thread..I was having problems posting....I was getting error messages.It has been happening often lately.I'm not sure if it is site oriented or not.Has anyone else had there reply just stop in it's tracks and not post? Again Thanks.

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Re: APOD: Abell 370: Galaxy Cluster Lens... (2019 Mar 19)

Post by bystander » Wed Mar 20, 2019 5:28 pm

sillyworm 2 wrote:
Wed Mar 20, 2019 4:25 pm
Thanks Art....as to posting it in the pertinent thread..I was having problems posting....I was getting error messages.It has been happening often lately.I'm not sure if it is site oriented or not.Has anyone else had there reply just stop in it's tracks and not post? Again Thanks.

There is also a place to report problems: Bugs? Problems? Report them here!

As for posting about a specific APOD, go to the APOD in question (M106?) and click on the Discuss link below the image.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
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zendae1

Re: APOD: Abell 370: Galaxy Cluster Lens... (Split from 2019 Mar 20)

Post by zendae1 » Wed Mar 20, 2019 6:42 pm

Is this working yet?

zendae1

Re: APOD: Abell 370: Galaxy Cluster Lens... (Split from 2019 Mar 20)

Post by zendae1 » Wed Mar 20, 2019 6:43 pm

Trying again; this has to do with yesterday's. I am having a great deal of trouble posting.



To neufer, ty for providing the size of the painting. You have sent me on a journey re this painting, which I cannot believe I never knew about!

"The Earth is, itself, bombarded both by high energy cosmic rays & by flares from a very near star and life persists."
lol a very near star...

This area is not at all a strong point for me, but considering that everything in an almost but not quite 'closed system' may be a contributor to life in that system, it follows that cosmic rays/flares may actually have been necessary for the spark of life to initiate. These 2 things make for ionization, which is a chemical change in the atmosphere, and life is chemistry. So perhaps the jets in that galaxy are actually contributing (even catalytic) nurturers!

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Re: APOD: Abell 370: Galaxy Cluster Lens... (Split from 2019 Mar 20)

Post by bystander » Wed Mar 20, 2019 7:27 pm

zendae1 wrote:
Wed Mar 20, 2019 6:43 pm
Trying again; this has to do with yesterday's. I am having a great deal of trouble posting.
bystander wrote:
Wed Mar 20, 2019 5:28 pm
There is also a place to report problems: Bugs? Problems? Report them here!

As for posting about a specific APOD, go to the APOD in question (Abell 370?) and click on the Discuss link below the image. (edited)
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor